Poly[l2-L-alanine-l3-nitrato-sodium(I)]

Kristof Van Hecke,a Els Cartuyvels,b Tatjana N. Parac-

Vogt,b Christiane Gorller-Walrandb and Luc Van

Meervelta*

aBiomolecular Architecture, Katholieke Universiteit Leuven, Department of Chem-

istry, Celestijnenlaan 200F, B-3001 Leuven (Heverlee), Belgium, and bLaboratory of

Coordination Chemistry, Katholieke Universiteit Leuven, Department of Chemistry,

Celestijnenlaan 200F, B-3001 Leuven (Heverlee), Belgium

Correspondence e-mail: luc.vanmeervelt@chem.kuleuven.be

Received 10 May 2007; accepted 9 August 2007

Key indicators: single-crystal X-ray study; T = 100 K; mean �(C–C) = 0.003 A;

R factor = 0.037; wR factor = 0.092; data-to-parameter ratio = 10.2.

The title compound, [Na(NO3)(C3H7NO2)]n, was obtained

unintentionally as the product of an attempted reaction of

sodium molybdate in aqueous solution and the amino acid

l-alanine (ala), in order to obtain a �-type octamolybdate,

Na4[Mo8O26(ala)2].18H2O, coordinated by l-alanine. The

coordination geometry around the Na atom can be considered

as trigonal–bipyramidal, with three bidentate nitrate anions

coordinating through their O atoms and two l-alanine

molecules each coordinating through one carboxylate O atom.

Related literature

For related literature, see: Allen (2002); Cindric et al. (2006);

Fujita et al. (1992); Pope (1983); Pope & Mueller (1994);

Rajagopal et al. (2003); Rhule et al. (1998); Yamase (1993);

Yamase et al. (1996, 1999).

Experimental

Crystal data

[Na(NO3)(C3H7NO2)]Mr = 174.10Orthorhombic, P212121

a = 5.3477 (3) Ab = 9.1719 (6) Ac = 13.5284 (8) A

V = 663.55 (7) A3

Z = 4Cu K� radiation� = 1.98 mm�1

T = 100 (2) K0.5 � 0.3 � 0.2 mm

Data collection

Bruker SMART 6000diffractometer

Absorption correction: multi-scan(SADABS; Bruker, 1997)Tmin = 0.431, Tmax = 0.673

6562 measured reflections1241 independent reflections1170 reflections with I > 2�(I)Rint = 0.048

Refinement

R[F 2 > 2�(F 2)] = 0.037wR(F 2) = 0.092S = 1.101241 reflections122 parametersOnly H-atom coordinates refined

��max = 0.32 e A�3

��min = �0.47 e A�3

Absolute structure: Flack (1983),480 Friedel pairs

Flack parameter: 0.10 (12)

Data collection: SMART (Bruker, 1997); cell refinement: SAINT

(Bruker, 1997); data reduction: SAINT; program(s) used to solve

structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine

structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

PLATON (Spek, 2003); software used to prepare material for

publication: PLATON.

The FWO–Vlaanderen and KULeuven are gratefully

acknowledged for financial support.

Supplementary data and figures for this paper are available from theIUCr electronic archives (Reference: RT2007).

References

Allen, F. H. (2002). Acta Cryst. B58, 380–388.Bruker (1997). SADABS (Version 2.10), SAINT (Version 5/6.0) and SMART

(Version 5.625). Bruker AXS Inc., Madison, Wisconsin, USA.Cindric, M., Novak, T. K., Kraljevic, S., Kralj, M. & Kamenar, B. (2006). Inorg.

Chim. Acta, 359, 1673–1680.Flack, H. D. (1983). Acta Cryst. A39, 876–881.Fujita, H., Fujita, T., Sakurai, T., Yamase, T. & Seto, Y. (1992). Tohoku J. Exp.

Med. 168, 421–426.Pope, M. T. (1983). Heteropoly and Isopoly Oxometalates. Berlin: Springer-

Verlag.Pope, M. T. & Mueller, A. (1994). Polyoxometallates: From Platonic Solids to

Anti-Retroviral Activity. Dordrecht, The Netherlands: Kluwer.Rajagopal, K., Krishnakumar, R. V., Subha Nandhini, M., Ravikumar, K. &

Natarajan, S. (2003). Acta Cryst. E59, m562–m564.Rhule, J. T., Hill, C. L. & Judd, D. A. (1998). Chem. Rev. 98, 327–357.Sheldrick, G. M. (1990). Acta Cryst. A46, 467–473.Sheldrick, G. M. (1997). SHELXL97. University of Gottingen, Germany.Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13.Yamase, T. (1993). Mol. Eng. 3, 241–262.Yamase, T., Fukuda, N. & Tajima, Y. (1996). Biol. Pharm. Bull. 19, 459–465.Yamase, T., Inoue, M., Naruke, H. & Fukaya, K. (1999). Chem. Lett. 28, 563–

564.

metal-organic compounds

m2354 # 2007 International Union of Crystallography doi:10.1107/S1600536807039438 Acta Cryst. (2007). E63, m2354

Acta Crystallographica Section E

Structure ReportsOnline

ISSN 1600-5368

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Acta Cryst. (2007). E63, m2354 [ doi:10.1107/S1600536807039438 ]

Poly[ 2-L-alanine- 3-nitrato-sodium(I)]

K. Van Hecke, E. Cartuyvels, T. N. Parac-Vogt, C. Görller-Walrand and L. Van Meervelt

Comment

Polyoxometalates (POMs) can be considered as oligomeric aggregates of metal cations, bridged by oxide anions that formby self-assembly processes (Rhule et al., 1998). There are two generic families of POMs, the isopolyoxometalates, that

contain only d0 metal cations and oxide anions and the heteropolyoxometalates, that contain one or more p-, d-, or f-blockheteroatoms in addition to the other ions (Pope, 1983; Rhule et al., 1998).

The medicinal features of these compounds cover a variety of important biological activities, such as the inhibition ofspecific enzymes or antiviral and antitumor activity (Pope and Mueller, 1994; Rhule et al., 1998). When used in combinationwith β-lactam antibiotics, polyoxotungstates enhance the antibiotic effectiveness against otherwise resistant strains of bac-

teria (Yamase et al., 1996). The heptamolybdate, [NH3Pri]6[Mo7O24]·3H2O had shown a potent in vivo antitumor activity

(Fujita, et al., 1992), which has been explained by repeated redox cycles of [Mo7O24]6− in the tumor cells (Yamase, 1993).

The biomedical investigations of polyoxomolybdates containing amino acids or even peptides (Yamase et al., 1999) havebeen focused upon finding polyoxomolybdates with both improved activity against cancer and clinical safety profiles.

The reported structure Na(NO3)C3H7NO2 was obtained unintentionally as the product of an attempted reaction of sodium

molybdate in aqueous solution and the amino acid L-alanine, in order to obtain a γ type octamolybdate, coordinated byL-alanine Na4[Mo8O26(ala)2].18H2O (Cindrić et al., 2006). In contrast to Cindrić et al., L-alanine was used instead of

D,L-alanine.

The asymmetric unit consists of one sodium and one nitrate ion and one L-alanine molecule.

The coordination geometry around the sodium atom can be considered as trigonal bipyramidal, with three bidentatenitrate anions coordinating through their oxygen atoms and two L-alanine molecules, each coordinating through one carboxyloxygen atom (Figure 1,2).

Three nitrate anions are bidentate coordinating to the sodium atom (2.612 (2)–2.771 (2) Å), forming one plane, parallelwith the (110) plane. The third nitrate oxygen atoms are coordinating to other symmetry equivalent sodium atoms, extendingthe plane formed. Almost perpendicular to this plane, two L-alanine molecules are coordinating to the sodium atom, eachthrough one carboxyl oxygen atom (2.3651 (16) and 2.3891 (17) Å). The other carboxyl oxygen atoms are coordinated tosodium atoms in the planes above and beneath, respectively. Hence, infinite planes parallel with (110) are formed by thenitrate anions and the sodium atoms and these are perpendicularly linked to each other by L-alanine molecules (Figure 3).

Intermolecular hydrogen bonds are observed between N1(H1A)···O(1)[1/2 + x,-1/2 − y,2 − z] (1.92 (4) Å),N1(H1B)···O(5)[1/2 + x,1/2 − y,2 − z] (2.10 (3) Å) and N1(H1C)···O(2)[1 + x,y,z] (1.87 (4) Å) and an intramolecular hydro-gen bond is found for N1(H1B)···O(2) (2.44 (3) Å).

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Only four structures of alanine coordination complexes are found in the CSD (Version 5.28) (Allen, 2002). Only in oneof them (Rajagopal et al., 2003), two alanine molecules are coordinated to the same cobalt ion. Concerning the nitrate ions,the reported structure is the first structure where three nitrate ions are coordinated to a sodium atom.

Experimental

L-Alanine (0.18 g, 2 mmol) was added to an aqueous solution of Na2MoO4 (0.484 g, 2 mmol) and the solution was acidified

by addition of HNO3 to pH 3.4. Colourless crystals of the title compound were obtained after standing for 5 days at room

temperature 0.02 g, 10%). L-Alanine and Na2MoO4 were purchased from Acros Organics (Geel, Belgium).

Refinement

All hydrogen atoms could be located in a difference Fourier map, and were further refined unrestrained with isotropictemperature factors fixed at 1.5 times Ueq of the parent atoms for the methyl and ammonia groups and 1.2 times Ueq of

the parent atom for the H2(C2) atom.

Figures

Fig. 1. Coordination geometry of the title compound, showing atom-labelling scheme and50% probability displacement ellipsoids. Hydrogen atoms are drawn at arbitrary size.

Fig. 2. Packing diagram of the title compound.

Poly[µ2-L-alanine-µ3-nitrato-sodium(I)]

Crystal data

[Na(NO3)(C3H7NO2)] F000 = 360

Mr = 174.10 Dx = 1.743 Mg m−3

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Orthorhombic, P212121Cu Kα radiationλ = 1.54178 Å

Hall symbol: P 2ac 2ab Cell parameters from 2690 reflectionsa = 5.3477 (3) Å θ = 5.8–70.3ºb = 9.1719 (6) Å µ = 1.98 mm−1

c = 13.5284 (8) Å T = 100 (2) K

V = 663.55 (7) Å3 Rod, colourlessZ = 4 0.5 × 0.3 × 0.2 mm

Data collection

Bruker SMART 6000diffractometer 1241 independent reflections

Radiation source: fine-focus sealed tube 1170 reflections with I > 2σ(I)Monochromator: crossed Göbel mirrors Rint = 0.048

T = 100(2) K θmax = 70.3º

ω and φ scans θmin = 5.8ºAbsorption correction: multi-scan(SADABS; Bruker, 1997) h = −6→6

Tmin = 0.431, Tmax = 0.673 k = 0→116562 measured reflections l = 0→16

Refinement

Refinement on F2 Only H-atom coordinates refined

Least-squares matrix: full w = 1/[σ2(Fo

2) + (0.0662P)2]where P = (Fo

2 + 2Fc2)/3

R[F2 > 2σ(F2)] = 0.037 (Δ/σ)max < 0.001

wR(F2) = 0.092 Δρmax = 0.32 e Å−3

S = 1.10 Δρmin = −0.47 e Å−3

1241 reflectionsExtinction correction: SHELXL97,Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4

122 parameters Extinction coefficient: 0.046 (3)Primary atom site location: structure-invariant directmethods Absolute structure: Flack, 1983

Secondary atom site location: difference Fourier map Flack parameter: 0.10 (12)Hydrogen site location: inferred from neighbouringsites

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance mat-rix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlationsbetween e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment ofcell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, convention-

al R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculat-

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ing R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twiceas large as those based on F, and R– factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

x y z Uiso*/Ueq

C1 0.6356 (4) 1.05721 (19) −0.00853 (15) 0.0078 (4)C2 0.3525 (4) 1.0453 (2) 0.00305 (15) 0.0090 (4)C3 0.2757 (4) 0.8870 (2) 0.02082 (14) 0.0136 (4)H2 0.300 (5) 1.109 (3) 0.0538 (19) 0.016*H1A 0.247 (7) 1.201 (3) −0.0929 (19) 0.020*H3A 0.322 (5) 0.825 (3) −0.033 (2) 0.020*H1B 0.287 (6) 1.064 (3) −0.140 (2) 0.020*H3B 0.095 (6) 0.881 (3) 0.028 (2) 0.020*H1C 0.062 (6) 1.080 (3) −0.087 (2) 0.020*H3C 0.348 (6) 0.841 (3) 0.082 (2) 0.020*N1 0.2284 (4) 1.10123 (18) −0.08786 (11) 0.0082 (3)N2 0.7554 (4) 0.71413 (16) 0.24472 (10) 0.0087 (3)Na1 0.75451 (17) 1.04449 (8) 0.23836 (5) 0.0127 (3)O1 0.7615 (3) 1.09249 (14) 0.06664 (8) 0.0097 (3)O2 0.7253 (3) 1.02859 (15) −0.09235 (10) 0.0122 (3)O3 0.5568 (3) 0.7841 (2) 0.24054 (13) 0.0209 (4)O4 0.9608 (3) 0.7753 (2) 0.23456 (13) 0.0201 (4)O5 0.7487 (4) 0.57822 (15) 0.26006 (9) 0.0211 (4)

Atomic displacement parameters (Å2)

U11 U22 U33 U12 U13 U23

C1 0.0083 (9) 0.0061 (9) 0.0090 (9) 0.0009 (7) −0.0015 (8) 0.0025 (7)C2 0.0072 (9) 0.0125 (9) 0.0072 (9) −0.0007 (8) 0.0004 (7) −0.0005 (8)C3 0.0106 (10) 0.0135 (9) 0.0166 (10) −0.0021 (10) 0.0000 (9) 0.0047 (7)N1 0.0056 (8) 0.0122 (8) 0.0067 (7) 0.0012 (8) 0.0001 (7) −0.0007 (5)N2 0.0103 (8) 0.0103 (7) 0.0056 (7) −0.0002 (8) −0.0003 (8) −0.0019 (5)Na1 0.0135 (4) 0.0164 (4) 0.0084 (4) −0.0005 (4) −0.0010 (4) 0.0027 (2)O1 0.0089 (6) 0.0119 (6) 0.0082 (6) 0.0011 (7) −0.0022 (7) −0.0005 (4)O2 0.0086 (7) 0.0214 (8) 0.0067 (6) 0.0002 (7) 0.0014 (6) −0.0014 (5)O3 0.0142 (8) 0.0329 (9) 0.0157 (8) 0.0120 (7) −0.0030 (7) −0.0045 (9)O4 0.0142 (8) 0.0264 (8) 0.0197 (9) −0.0095 (7) 0.0053 (7) −0.0051 (7)O5 0.0418 (10) 0.0106 (7) 0.0108 (6) −0.0020 (9) 0.0036 (9) −0.0012 (5)

Geometric parameters (Å, °)

C1—O2 1.259 (3) N1—H1B 0.84 (3)C1—O1 1.262 (2) N1—H1C 0.91 (3)C1—C2 1.526 (3) N2—O4 1.241 (3)C2—N1 1.489 (2) N2—O3 1.242 (3)C2—C3 1.528 (3) N2—O5 1.264 (2)C2—H2 0.94 (3) N2—Na1 3.0312 (17)

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C3—H3A 0.96 (3) Na1—O1 2.3647 (13)C3—H3B 0.97 (3) Na1—O3 2.612 (2)C3—H3C 1.00 (3) Na1—O4 2.705 (2)N1—H1A 0.92 (3)

O2—C1—O1 125.16 (19) C2—N1—H1C 110.9 (19)O2—C1—C2 117.11 (17) H1A—N1—H1C 108 (3)O1—C1—C2 117.72 (17) H1B—N1—H1C 106 (3)N1—C2—C1 109.44 (16) O4—N2—O3 121.22 (17)N1—C2—C3 109.74 (16) O4—N2—O5 119.3 (2)C1—C2—C3 110.54 (17) O3—N2—O5 119.5 (2)N1—C2—H2 104.8 (17) O4—N2—Na1 63.02 (11)C1—C2—H2 109.2 (17) O3—N2—Na1 58.74 (12)C3—C2—H2 112.9 (17) O5—N2—Na1 171.99 (11)C2—C3—H3A 111.7 (17) O1—Na1—O3 100.82 (6)C2—C3—H3B 109.6 (18) O1—Na1—O4 98.33 (6)H3A—C3—H3B 108 (2) O3—Na1—O4 47.99 (5)C2—C3—H3C 115.1 (16) O1—Na1—N2 102.35 (5)H3A—C3—H3C 106 (2) O3—Na1—N2 23.98 (6)H3B—C3—H3C 106 (2) O4—Na1—N2 24.14 (6)C2—N1—H1A 110.8 (18) C1—O1—Na1 137.35 (13)C2—N1—H1B 112.4 (19) N2—O3—Na1 97.28 (13)H1A—N1—H1B 108 (3) N2—O4—Na1 92.84 (13)

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Fig. 1

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Fig. 2